CHRIS BURY: You've performed at least three successful surgeries on conjoined twins, but these were all done with infants, with children. What made this particular operation [this week] different, and perhaps more difficult?

DR. BEN CARSON: The big difference here is that these young ladies had been fused for 29 years, so their brains were extraordinarily adherent to each other. So we didn't have the advantage of being able to establish planes and to pull them apart.

Number two, the bones were incredibly thick, particularly along the base, like a brick. And number three, they're large individuals. With the babies, we can work on the front, flip them over, work on the back. This was not going to be a possibility with individuals of a combined of 100 kilograms or more. So those were things that precluded us from being able to do things in the normal fashion. …

BURY: Did they meet the definition of informed consent? … I read that one of the surgeons on the team actually argued to them that they shouldn't undergo this operation.

CARSON: More than one. They made a very strong bid to dissuade them from having surgery, but again, they continued to reiterate that their lives, as they existed, were worse than death.

BURY: Was this, though, at the end of the day, elective surgery? I mean, after all, they had been living as conjoined twins for 28 years. They could have gone on living for some number of years beyond.

CARSON: They probably would have lived on for several more years. As you probably know, conjoined twins frequently die considerably earlier than the general population, simply because complications that might not normally affect someone have profound effects on them. …

Again, you're looking at a situation where you would probably have to walk a mile in their shoes to understand their psyche. Because most of us would say, "It can't be that bad to be joined to somebody," but I wonder how many of us would say that if every decision that we ever made in life had to be by committee — when to turn, when to eat, when to go to the bathroom. Particularly if you're a highly intelligent person who's ambitious. I suspect that, in fact, many people might have a much better understanding of their situation if they could just spend a week like that. …

Progress In Practice

BURY: When it became clear that the operation was not a success, you certainly knew there were going to be recriminations and second-guessing.

CARSON: Yes, of course, which is always the case, throughout history. If you look at almost any type of very complex surgery that is done for the first time, in many cases the results are not good — the difference being that those cases are not usually done under the microscope of the entire international community, and therefore, the same kinds of questions are not necessarily asked.